Routine treatment of sleep disorders such as Obstructive Sleep Apnea (“OSA”), hypopnea, and others is often provided in home settings by the use of Positive Airway Pressure (“PAP”) devices. OSA typically results from relaxation of a patient's muscles during sleep, causing partial or complete obstruction of the patient's airway. Snoring is associated with partial obstruction. Cessation of breathing, or apnea, is associated with complete obstruction, and may lead to choking, partial or complete awakening, or worse medical complications, such as cardiovascular disease. A related sleep occurrence called hypopnea is an incident of shallow breathing, which is often inconsequential but can have significant medical impact if prolonged. PAP devices include a mask placed over a patient's nose and/or mouth, through which air blows into the patient's airway while the patient sleeps. The air pressurizes the patient's airway to prevent or mitigate apnea and hypopnea, reducing medical risks and improving the patient's quality of sleep.
The therapeutic conditions (e.g., pressure) to be supplied by a PAP device are usually determined in a sleep lab. Sleep labs are usually characterized by extensive equipment in a fixed location used only at night. Sleep lab costs are generally high, since sleep lab equipment is not typically used during regular business hours, and since technical personnel are paid higher wages to work through the night. Scheduling sleep lab sessions entails matching the availability of the sleep lab facility and personnel to the availability of a patient for an overnight stay. These cost and scheduling issues generally work to restrict the practical time for sleep lab studies for a given patient to one night. The same issues work to discourage sleep lab sessions for follow-up care or post treatment evaluation. The sleep lab bed, surroundings, and equipment also constitute an unfamiliar sleep environment for the patient, which, unfortunately, can result in a disturbance to the very sleep patterns being evaluated. Studies show that 2-4 weeks of data may be required to determine the optimal therapeutic pressure for a patient.
The therapeutic conditions supplied by a PAP device and developed in the sleep lab are then fixed for future use of the PAP device in the patient's home. These therapeutic conditions may not be ideal for the patient, in that the patient's sleep patterns may be different at home than in the sleep lab setting. The therapeutic conditions best suited for the patient may also be affected from time to time by variables in the patient's life that were not present during a sleep lab session, e.g.: (a) prior consumption of a heavy meal, alcohol, and/or certain medications, (b) variations in patient's emotional state, stress level, sleep phase and/or total sleep time, and (c) the presence of upper airway allergies and/or infections.